A Message Of Import

Not to pick on Indonesia this morning, since the following warning could apply to many other travel destinations, but we’ve an interesting warning from the Western Australia Health Department for visitors returning from Bali.

Western Australians are being reminded to take precautions against infectious diseases when travelling, with a particular emphasis on people holidaying in Bali.

Director of Communicable Disease Control Dr Paul Armstrong said that travellers needed to take precautions against a range of infectious diseases, including mosquito borne diseases like Dengue fever, gastroenteritis, sexually transmissible infections, and rabies.

"Dengue fever notifications in WA have increased from 16 in 2006 to 151 in the first half of 2010, with most of these cases associated with travel to Bali," Dr Armstrong said.

Symptoms can occur within three to 14 days of being bitten and include fever, severe headache, aching joints and muscles, pain behind the eyes, nausea, vomiting and a rash.

Dr Armstrong said that while most people recovered completely from the illness, there was a risk of developing a rare but potentially fatal form of the disease.

The mosquito that transmits Dengue fever commonly bites during the day and in shady, indoor situations. It is important to avoid being bitten by mosquitoes by taking precautions such as:

Using personal repellents containing diethyl toluamide (DEET) or picaridin. The most effective and long-lasting formulations are lotions or gels. Some natural or organic repellents may provide lesser protection, and

Ensuring infants and children sleeping or playing indoors during the day are adequately protected against mosquito bites, preferably with suitable clothing or bed nets. Only infant-strength repellents should be used on children.

Dr Armstrong said gastroenteritis was also very common in travellers and could be caused by a range of bacteria, viruses and parasites. Nearly one third of Salmonella infections notified in WA so far this year were acquired overseas, mostly in Bali.

"Travellers to developing countries need to be very careful with the food they eat and the water they drink. To reduce the risk of gastroenteritis people should avoid eating salads, raw or runny eggs and fruit that is eaten with the skin on."

Dr Armstrong said that sexually transmissible infections, such as gonorrhoea, chlamydia and HIV are also a risk in travellers who have casual sex, highlighting the importance of heeding safe sex messages, especially the use of condoms.

Rabies is also a serious risk in Bali. About 60 Balinese have died from rabies in the past two years after animal bites, mostly from dogs. Many of these bites have been sustained in the southern areas of Bali which are popular with tourists.

Dr Armstrong said that any mammal in Bali, including dogs, cats, bats and monkeys, should be considered a potential source of rabies infection. Risky exposures include bites and scratches.

Travellers bitten or scratched by an animal in Bali or other countries should urgently seek medical attention, and will usually need to complete a course of post-exposure vaccinations. Rabies is universally fatal once symptoms develop.

In our increasingly mobile society, and with the ability to literally travel half-way around the world in less than 24 hours, the risks of importing normally rare and exotic pathogens to previously unaffected areas increases.

When it took days or even weeks to cross an ocean, people who contracted an illness generally showed signs of infection before arriving in a new country.

A person can be bitten by a Dengue carrying mosquito in Bali today and be in Los Angeles for breakfast tomorrow morning.

And a week later start showing symptoms. And of course, some people may carry it asymptomatically.

Six weeks ago the CDC’s MMWR released a report on the re-emergence of locally acquiredDengue Fever in Key West, Florida after an absence of 70 years.

A bit ironically, the first case was detected – not in Key West – but in New York state by a particularly astute doctor who saw a woman returning from a Florida vacation and recognized her symptoms.

While these cases were acquired locally, the virus was probably reintroduced to the area by an infected traveler or visitor who was bitten by a mosquito, and that mosquito went on to bite others.

In mid-June the MMWR came out with a new report on Travel Associated Dengue in the United States between 2006 and 2008.

This surveillance pre-dates the Key West outbreak, and as the study reports, `Clinically recognized cases of travel-associated dengue likely underestimate the risk for importation because many dengue infections are asymptomatic or mildly symptomatic’.

In 2007, Chikungunya spread rapidly across the Indian Ocean, hitting Reunion Island particularly hard. It is essentially a tropical disease, spread by the Aedes mosquitoes, and until recently was found only in Africa and parts of the Indian Ocean.

It is hard to see, but if you look closely, you'll also see that Italy is colored in as an affected country.

Yes, Italy.

A traveler, returning from India, brought the virus to Italy in 2007 with more than 290 cases reported in the province of Ravenna, which is in northeast Italy.

You see, while the virus isn't normally found in Europe, the vector, the Aedes mosquito, is. All it took was one infected person to arrive with the virus, and the chain of transmission began, ultimately infecting nearly 300 people.

While once we were protected from rare, exotic diseases by vast oceans and lengthy travel times, today public health officials in developed countries must be on alert for practically any disease or illness.

An outbreak of an infectious disease in Asia or the Caribbean today may well become a problem in Atlanta, London, or Sydney tomorrow.

All of which illustrates the necessity for supporting our public health infrastructures.

While not as glamorous or as lucrative as private practice, public health is literally the thin white line that stands between modern society and epidemics of death and misery.

In the coming years, with the encroachment of new zoonotic diseases along with a resurgence of old viral and bacterial foes, their work will take on an even greater importance.

In these times of tightening budgets, and economic downturns, we ignore their funding needs at our own considerable risk.